Elephants, duikers and shrews, part of a diverse regional portrait

From famous forest elephants to the obscure Charaxes butterflies, the Congo River Basin has earned a global reputation for the variety of wildlife found inside its forests.

These contain a major share of the African continent’s biodiversity: more than 60% of butterflies and passereaux birds, and more than 80% of African primates.1

Some of the world’s most spectacular and endangered wildlife lives in Central Africa, including one-half of the remaining elephants on the continent. Ten thousand species of plants (of which 3,000 are found nowhere else), 1,000 species of birds, and 400 species of mammals2 , 216 species of amphibians, 280 species of reptiles and more than 900 species of butterflies are found here.

But while these forests are rich in the numbers of species by world standards, they actually have smaller numbers than other tropical rainforests throughout the planet.

The rivers of the Congo River Basin are especially rich in aquatic biodiversity, with most species unique to the region (endemic).

Species biodiversity, peaks and troughs across the Basin

A conspicuous feature of the Congo River Basin forests is that the diversity of species varies greatly from one place to another.3

Peaks of biodiversity and endemism (number of species found nowhere else) are found in the Cameroon highlands, the western equatorial forests of Cameroon and Gabon, the coastal mangroves, the Albertine Rift highlands and the eastern lowland forests of the Democratic Republic of Congo (DRC).4 Frogs and birds abound in mountain areas, where many endemic species are found.5

Endemic species vary considerably in range and size. The pygmy chimpanzee, or bonobo (Pan Paniscus), is distributed throughout the forests of the Congo River Basin and the okapi (okapia johnstoni) is found across north and northeastern DRC.

Other species, such as the pygmy hippo (Hexaprotodon liberiensis) have a very fragmented distribution, and are only found along coastal Atlantic Africa.6

Factors affecting distribution of wildlife

Rivers such as the Congo and the Ouabangui have played critical roles in limiting the range of several species, especially mammals. Time has also contributed to this phenomenon.

Over millions of years, dry and wet periods have alternated in the Congo River Basin, leading to the containment of several species in very specific habitats with distinct climates.